ABSTRACT

Resistance welding is a joining process belonging to the pressure welding sector. With its locally applied heat and pressure it has an obvious relationship with the forge welding technique practised by blacksmiths when joining metal. Resistance welding is extensively used for the mass production assembly of the all-steel body and its component sheet metal parts. Resistance spot welding is basically confined to making welds of approximately 6 mm diameter between two or more overlapping sheet metal panels. Projection welding involves the joining of parts by a resistance welding process which closely resembles spot welding. This type of welding is widely used in attaching fasteners to structural members. Seam welding is like spot welding except that the spots overlap each other, making a continuous weld seam. Flash welding is used to butt or mitre sheet, bar, rod, tube and extruded sections. When shear testing spot welds produced when welding together two HSLA steels, partial spot-weld failure may occur.